Valve mechanism for rock drills



Sept. 29, 1936. c. A. HULTQUIST 2,055,49?

VALVE MECHANISM FOR ROCK DRILLS Filed Now 28, 1934 2 Sheets-Sheet lINVENTOR.

6Zar/es A. f/u/famls/ BY Jun/now} ATTORNEY?! 9 9 c; A. HULTQUIST ,4

VALVE MECHANISM FOR ROCK DRILLS Filed Nov. gs, 1954 2 Shets-Sheet 2 V/MMATTORNEY I: ha/76544. 246 ;21 :152

are!) STATES? FATENT OFFICE-.1

2,055,497 VALVE MECHANISM FOR ROCK DRILLS Charles A. Hultquis't, LosAn'gles, Calif, assignor to" Independent Pneumatic Tool (30;, Chicago;

Ill., acorporation of Delaware Application November 28, 1934-, SerialNoi755,155

10 Claims.

My invention relates to valve mechanisms-for rock drills, and the objects of my invention are:

First, to provide a valve mechanism for rock drills which provides acorrect distribution of the.- compressed fluid .used in. operating. thetool in order to obtain greater drilling speedwith reduced powerconsumption; p

Second, to provide a valve mechanism of this class for rock drills soconstructed: that more compressed fluid will in its operation to eith beadmitted by the valve erendof thecylind'erbor'e at the start of eachstroke of the drill hammer than later in the strokes; and

Third, to provide a new an valve and valve chest economical ofconstruction,

(1 novel distributing which is verysimple and eflicientin its action,-

and which will not readily deteriorate or get out of order.

With th ese and other objects in view as willappear hereinafter, myinvention consists ofcertain novel features of construction, combinationand arrangement of parts and portions as will be hereinafter describedin detail and particu-- larly set forth in the appended cl'aims;reference 5 being had to the accompanying drawings and to the charactersof reference thereon which form a part of this application, inwhich:

'Figure 1 is a back end view with a portion of the f the rockdrillthrottle broken away and in section to facilitate the illustration; 2islongitudinal sectional line 22 oiFig.'l and ing valve in its re fluidto the rear en tion for drivin ward or working stroke of the headthrough 3- g the hammer p1 Fig. 3 is a sectional view 3*of Fig. l, andFig. 4

f the drill on the the-air distributview 0 showing arward position foradmitting d of the cylinder bore-in posiston on its for is a fragmentarysectional view on an enlarged scale through 44 of tributing valve in itsFig. 2 andshowing the disforward position for ad mitting fluid to theforward end of the cylinder bore for driving the or return stroke.

Similar characters of hammer piston on its rear reference refertosimilar Q parts and portions throughout the several views" of thedrawings.

As in the convention al rock" drill of this class;

my rock drill is provided with a back head*-5 which operates a thro todifierent positions is held in varied positionsby a ratchetpawlandspring, as shown best in Figs. 1 andB ofthe drawings, whichareconventional and may be'omittedg if desired, without afiecting theoperation of my valve mechanism. Screwed into the housing 6" at theopposite end from the throttle handle 8 is: an air inlet spud 9 which isthe main air inlet to the; rock drill. The head 5 is also provided 5with aehole lfl'which is adapted to receive the handle-in theconventional manner for supporting: the drill duringthe drillingoperations.

Seated partly in the back head 5 and partly in: the counter bore H ofthe rear cylinder l2 107' is a conventional ratchet mechanism l3 whichconsists of the" conventional ratchet ring, pawls, springs and the headof the rifle bar I l, not shown in detail excet the. end of the riflebar I74. This rifle bar M is provided withhelical 15- flutes whichareadapted to engage helical ridges cut in the rifle nut" |5i which isscrewed into. the hammer piston l6; thus providing means for rotatingthe hammer piston IB- when it travels back and forth m the cylinder I2that this rotating movement is conveyed to the. chuck driver IT byreason of flutes cut on the hammer extensiom l'8 which engage notches l9in t'he' chuck drivet N. This in turn rotates the drill steel which" issupported in the chuck driver ll by means ofa hexagon shank H. The backhead 5 and f'ronthead 2-2" and the intermediate parts are held in rigidalinement and position by two side bolts 23g shown in Fig. 1 of thedrawings, which pass through: lugs in the back head 5 and front head 22It will be here noted that the structure so far desc'ribed iri detaili's subst'antially' conventional in form of pneumatic rock drills ofthis" class but-is necessary for combinative' relation-with the valvemechanism described hereinafter.

Mounted inthe counter bore H of the rear cylinder l-Tis' aval've chest25 and reciprocally mounte'd inthis-v lye chest 25 is-a tubular slidingdistributing valve which slides on the bearing 2 6" which bearingZE-"i'smade integral with the flange 21'- Which is clamped incentralalinement betweenthe rearward end of the valve chest 25 and the ratchetmechanism l'3-in the bore II. The valve'bearing 26- and flange 21 arehollow 4-5 and therifle ban l4 extends through the valvebearing-"ifiandfl'ange 21$ The'valve' chest 25 is provided with acentral fluid supply groove 28' and-with fluid reservoir chambers 29 and30 on oppositesides thereo I bores-in the'ridges 31 and 32 ar e' o'flequal dimen sion's, while thebore in the ridge 33- is larger in'diameter tha'nthe bores in theridges 3| and 3.2,. and the bore in theri'dge 34 is larger than the bore inthe ridge 33*; A counter 'bore 35 inthe 55 It will be noted f. The" diameters of the the front end 36 of thecylinder bore through inlet port 31. The central supply groovecommunicates with a throttle valve 1 and supply chamber 38 through ports39, shown best in Fig. 2 of the drawings.

' The distributing valve 24 has four flanges from its rear endforwardly, designated 4|), 4|, 42 and 43, shown best in Fig. 4 of thedrawings. The flanges 3| and 42 are of equal dimensions but smaller indiameter than the bores of the ridges 33 and 34 in which they operate,thus leaving spaces 4-2 and 45 between the flanges 4| and 42 and ridges33 and 34 which are constantly open for the flow of fluid into thechambers 29 and 33. The spaces 44 and 45 control the amount of fluidrequired for driving the hammer piston IS on its forward and rearwardstrokes. The two flanges 4B and 43 are of equal dimensions but thickerand of heavier construction than the flanges 4| and 42 because they.serve in conjunction with the ridges 3| and 32 as stops for limitingthe travel of the distributing valve 24. The flanges 40 and 43 arespaced on the valve in relation to the inner face of the ridges 3| and32 to provide the valve with a very short travel and against which theyseat intermittently and make an airtight joint. These flanges 4|] and 43are smaller in diameter than the flanges 4| and 42, therefore theflanges 4| and 42 have. a larger pressure area on their outer faces 45and Lil than the flanges 45 and 43 have on their inner faces 48 and 49.The difference in the diameters of the constrictions in the valvecheston opposite sides of the central inlet in the valve chest whichresults in a different space at the opposite sides of the inlet incooperation with the resultant varying static pressure provides meansfor facilitating the starting operation of the tool and also acceleratesthe movement of the valve while in operation.

It will behere noted that no confusion can occur in assembling thisvalve mechanism because the flanges M and 42 are spaced equally from thecenter of the valve 24 and are of the same dimensions as the flanges 30and 43, although smaller in diameter than the flanges 4| and 42, are ofequal dimensions and spaced equally from the middle of the valve.Therefore, it will be seen that the valve 24 will operate equally aswell if turned end for end, or reversed in position.

The operation of my valve mechanism is as follows: Referring generallyto Fig. 2 of the drawings, fluid under pressure enters the back head5through the inlet spud 9, shown in Figs. l'and l of'the drawings, intothe hollow portion 50 of the throttle valve 7. Thence through inlet port5|. inthe throttle valve 1 and the port 52 in the. back head 5 and intothe chamber 38. Thence through the supply ports 39 into the centralsupply groove'28 of the valve chest 25. Fromthere it is distributed bythe distributing valve 24. It will be noted thatthe valve 24 is shown inits rearward position in Fig. 2 of the drawings and the fluid flowsthrough the spaces 44 and 45 into the'reserve chambers 29 and 3|], theflange lljbeing seated against the inner side of the ridge 3|. From thechamber 36 thefluid flows throughrthe opening 53 into the rear end 54 ofthe cylinder bore where it operates the hammer piston I6 driving itforward on its working stroke. The fluid pressure against the outer sideof theflange 43 and the end face 55 of the valve. holds the valve in itsrearwardpositiom 2,055,497 rear end of the valve chest 25 communicateswith as shown in Fig. 2 of the drawings. In its forward travel thehammer piston it has passed over and closed the exhaust port 56, shownin Fig. 2 of the drawings, and is now compressing fluid in the front end36 of the cylinder bore. This compressed fluid flows through the port 31into the counter bore of the valve chest 25 where it acts on the rearend 5? and pressure area 58 of the valve 24. As the hammer piston l6continues on its forward or working stroke the exhaust port 55 isuncovered at the rear of the hammer piston l5 and exhaust is now takingplace in the rear end 54 of the cylinder bore.

As the pressure against the end face 55 and outer side of the flange 53of the valve 24 is lessened, the pressure created against the rear end51 and pressure area 58 moves the valve to its forward position, asshown in Fig. 4 of the drawings.

The shifting of the valve is arranged by applicants construction andmode of operation to occur a moment before the hammer extension |8strikes the end of the drill shank 2|. The fluid is now flowing throughpassages 44 and 59 into the counter bore 35, thence through the cylinderport 31 into the forward'end 36 of the cylinder bore for driving thehammer piston l6 rearwardly. On its return stroke the hammer piston l6passes over and closes the exhaust port 56 which causes compression inthe rear end 54 of the cylinder bore. As the hammer piston I6 continueson its rearward stroke it passes completely over the exhaust port 56.Exhaust is now taking place in the front end 36 of the cylinder bore. Asthe pressure diminishes against the end face 5? and outer side of theflange of the distributing valve 24, the pressure caused in the rearcylinder bore 55 acting on the end face 55 and the pressure area 60moves the valve to its rearward position and the hammer piston 6 willagain start on its forward stroke.

The above-described operation of the different parts will continue aslong as fluid under pressure flows into the groove 28 of the chest 25.

Because of the fluid reserve in the chambers 29 and 30, the fluidsupplied to drive the hammer piston I5 forwardly and rearwardly isgreater at the initial start of the stroke than at any other time. Thisprovides a quick start for the hammer piston Hi from each end of thecylinder bore which increases the speed of the hammer piston and morework is accomplished than would be possible by a valve mechanism wherethere are no reserve chambers.

.Though I have shown and described a particular construction,combination and arrangement of parts and portions, I do not wish to belimited to this particular construction, combination and arrangement butdesire to include in the scope of my invention the construction,combination and arrangement substantially as set forth in the appendedclaims.

Having thus described my invention, what I claim as newand desire tosecure by Letters Patent is:

1. In a valve mechanism for rock drills, a cylindrical bearing, a hollowtubular valve member slidable thereon provided with two relatively largediameter flanges in spaced relation at the middle thereof and with twosmaller diameter flanges one near each end of said valve member inspaced relation to the first mentioned flanges, a valve chestsurrounding said valve member, and constrictionsoverhanging the endflanges of said valve member and adapted to be engaged by" said flangeswith the backward and forward movement of said valve member, and a pairof in operative relation with the middle flanges of said valve member,one of said constrictions having a larger diameter bore than the other;and afluid conducting channel between said intermediate constrictions insaid valve chest.

2; In a valve mechanism for'rock drills, a cylindrical bearing, a hollowtubular valvemem ber slidable thereon provided with two relatively largediameter flanges in spaced relation at the middle thereof and with twosmaller diameter flanges one near eachend of said valve-member in spacedrelation to theflrst mentioned flanges, a valve chest surrounding saidvalve member, and constrictions overhanging the end flanges of saidvalvemember and adapted to be engaged by said flanges with the backwardand forward movement of said valve member, a pair of constrictions insaid valve chest intermediate the end constrictions in spaced relationto each other in operative relation with the middle flanges of saidvalve member, one of said constrictions having a larger diameter borethan the other, a fluid conducting channel between said intermediateconstrictions in said valve chest, and a counter bore at the rearwardend of said valve chest in communication therewith.

3. In a valve mechanism for rock drills, a cylindrical bearing, a hollowtubular valve member slidable thereon provided with two relatively largediameter flanges in spaced relation at the middle thereof and with twosmaller diameter flanges one near each end of said valve member inspaced relation to the first mentioned flanges, a valve chestsurrounding said valve member, and constrictions overhanging the endflanges of said valve member and adapted to be engaged by said flangeswith the backward and forward movement of said valve member, and a pairof constrictions in said valve chest intermediate the end constrictionsin spaced relation to each other in operative relation with the middleflanges of said valve member, one of said constrictions having a largerdiameter bore than the other, and a fluid conducting channel betweensaid intermediate constrictions in said valve chest, said chest providedwith two fluid chambers formed between the intermediate constrictionsand the outer constrictions of said valve chest.

4. In a valve mechanism for rock drills, a cylindrical bearing, a hollowtubular valve member slidable thereon provided with two relatively largediameter flanges in spaced relation at the middle thereof and with twosmaller diameter flanges one near each end of said valve member inspaced relation to the first mentioned flanges, a valve chestsurrounding said valve member, and constrictions overhanging the endflanges of said valve member and adapted to be engaged by said flangeswith the backward and forward move ment of said valve member, a pair ofconstrictions in said valve chest intermediate the end constrictions inspaced relation to each other in operative relation with the middleflanges of said valve member, one of said constrictions having a largerdiameter bore than the other, a fluid conducting channel between saidintermediate constrictions in said valve chest, and a counter bore atthe rearward end of said valve chest formed by one of saidconstrictions, said chest provided with two fluid chambers formedbetween: the: intermediate constrictions and the outer constrictions ofsaid valve chest 5.4 In a valve mechanism for rock drills, the.combination with a tubular flanged sliding valve of an annulartubularvalve chest provided with two spa'cedconstrictions extending inwardlyintermediate'the ends of said valve chest and leaving a fluid intakechannel between said constrictions; the bores of said constrictionsbeing of unequal diameter, and also providecl with two inwardlyextending outer constrictions spaced from said middle constrictions andleaving. annular fluid res ervoir' chambers. therebetween.

6i In: a valve mechanism for rock drills, the combination with-.atubular flanged sliding distributing valvefof an annular tubular valvechest provided with two spacedconstrictions extending inwardlyintermediate the ends of said valve chest 'and' 'leaving a fluid intakechannel between said constrictions, the bores of said constrictionsbeing of unequal diameter, and also provided with two inwardly extendingouter constrictions spaced from said middle constrictions and leavingannular fluid reservoir chambers therebetween, the bores of said outerconstrictions being of equal diameter.

7. In a valve mechanism for rock drills, the combination with a tubularflanged sliding distributing valve of an annular tubular valve chestprovided with two spaced constrictions extending inwardly intermediatethe ends of said valve chest and leaving a fluid intake channel betweensaid constrictions, the bores of said constrictions being of unequaldiameter, and also provided with two inwardly extending outerconstrictions spaced from said middle constrictions and leaving annularfluid reservoir chambers therebetween, the bores of said outerconstrictions being of equal diameter, said valve chest also providedwith a counter bore between the rear outer constrictions and the end ofsaid valve chest.

8. In a valve mechanism for rock drills, an annular tubular valve chestprovided with two spaced constrictions extending inwardly intermediatethe ends of said valve chest and leaving a fluid intake channel betweensaid constrictions, the bores of said constrictions being of unequaldiameter, also provided with two inwardly extending outer constrictionsspaced from said middle constrictions and leaving annular fluidreservoir chambers therebetween, the bores of said outer constrictionsbeing of equal diameter, and a tubular valve slidably mounted in saidvalve chest provided with outer flanges near the opposite ends of saidvalve of a diameter adapted to engage the inner side walls of said outerconstrictions of said valve chest and arranged to provide clearance forslight shiftable movement between said flanges and said outerconstrictions.

9. In a valve mechanism for rock drills, an annular tubular valve chestprovided with two spaced constrictions extending inwardly intermediatethe ends of said valve chest and leaving a fluid intake channel betweensaid constrictions, the bores of said constrictions being of unequaldiameter, also provided with two inwardly extending outer constrictionsspaced from said middle constrictions and leaving annular fluidreservoir chambers therebetween, the bores of said outer constrictionsbeing of equal diameter, and a tubular valve slidably mounted in saidvalve chest provided with outer flanges near the opposite ends of saidvalve of a diameter adapted to engage the inner side walls of said outerconstrictions of said valve chest and arranged to provide clearance forslight shiftable movement between said flanges and said outerconstrictions, said valve also provided with a pair of spaced flanges onthe middle portion of said valve positioned to operate in the bores ofsaid middle constrictions of said valve chest, said flanges being ofequal diameter whereby the spaces between said flanges and middle'constrictions are varied.

'10. In a valve mechanism for rock drills, an annular tubular valvechest provided with two spaced constrictions extending inwardlyintermediate the ends of said valve chest and leaving a fluid intakechannel between said constrictions, the bores V of said constrictionsbeing of unequal diameter,

also provided with two inwardly extending outer constrictions spacedfrom said middle constrictions and leaving annular fluid reservoirchambers therebetween, the bores of said outer constrictions being ofequal diameter, a tubular valve slidably mounted in said valve chestprovided with outer flanges near the opposite ends of said 1 valve of adiameter adapted to engage the inner side walls of said outerconstrictions of said valve chest and arranged to provide clearance forslight shiftable movement between said flanges and said outerconstrictions, said valve also provided with a pair of spaced flanges onthe middle portion of said valve positioned to operate in the bores ofsaid middle constrictions of said valve chest, said flanges being ofequal diameter whereby the spaces between said flanges and middleconstrictions are varied, and said valve provided with extended annularend portions spaced from the inner side of the bore of said outerconstrictions to provide pressure spaces for the sides of the flanges ofsaid valve. 7

CHARLES A. HULTQUIST.

